Conventional fibers are useful in a variety of applications including reinforcements, textiles, and acoustical and thermal insulation materials. The fibers can be formed from organic molten materials, such as polymers, and inorganic materials such as glass, rock, slag, and basalt. Continuous fibers are typically produced via stationary bushings for reinforcement and textile applications. Such fibers are typically coated with a size for protection against abrasion and for enhanced compatibility with resin matrices. The glass fibers are often further processed by combining them into continuous strands, yarns and rovings, or by chopping the glass fibers into preselected lengths defined by the end user. Where chopped, the resulting short, straight fiber segments may be mixed with other materials, wet processed into mats such as are used for shingles, or otherwise treated for use. While stationary bushings have significant operational lifetimes, their throughput is limited relative to rotary fiberizing techniques for producing glass fibers.
Short, straight fibers typical of conventional acoustical and thermal insulation materials are made by rotary fiberizing techniques and are interconnected by binders. In such techniques, molten material is delivered to an orificed centrifuge, commonly referred to as a spinner. Fibers produced by the spinner are drawn downward by a blower. Binder can optionally be sprayed onto the fibers as they are drawn downward. The fibers are then collected and formed into a continuous blanket. The blanket can then be cut into desired lengths called batts.
Fibrous material, in the form of blankets or a collection of fibers, may optionally be encapsulated with a film to form an encapsulated blanket. Typically, the film is wrapped around the fibrous material and sealed together at the edges so that the film completely covers the fibrous material. The film could also be supplied in the form of a bag and then placed over the fibrous material. Encapsulation is particularly desirable when the fibers are loosely entangled or unbonded with each other rather than bound into a sharply defined, compressible product by an organic binder. Encapsulating the fibers provides for easy handling of the loosely entangled fibers for further processing or for supplying the fibers to an end user.
Needlepunching or "needling" is commonly used in the textile industry and the needled fabrics are found in a wide range of products. Needling is accomplished by a needle loom which subjects the fabrics to a needling process in which needles are pushed through the fibers of the fabrics to further entangle the fibers. It is difficult to needle fibers because of their loose entanglement with each other and the difficulty of holding the fibers together as they are fed into a needle loom. To overcome this difficulty, the fibers are frequently subjected to precursor processing steps, such as, carding, blending with other fibers, or lubrication before being needled. Carding aligns the fibers in a generally parallel direction and entangles the fibers because of the curliness of the fibers, giving the fibrous blanket some rigidity or strength. The carding is typically accomplished by the action of opposing, rotating cylinders having thousands of metal teeth which can damage or break the fibers.
It would be desirable to produce a fibrous product having rigidity and stiffness, in which the method of producing the fibrous product does not subject the fibers to excessive damage. It would also be desirable to produce the fibrous product so that a large quantity of fibrous material can be processed and to reduce the costs of manufacturing by eliminating processing steps and reducing the environmental clean up costs.